Set of key buttons for a handset



FIG. 1 is a front view of a set of key buttons for a handset showing my new design; and

FIG. 2 is a front perspective view thereof;

FIG. 3 is a bottom view thereof;

FIG. 4 is a top view thereof; and,

FIG. 5 is a left side view thereof.

The broken line showing of the remainder of the handset is directed to environment and is for illustrative purposes only; the broken lines form no part of the claimed design. 

The ornamental design for a set of key buttons for a handset, as shown and described. 